Proton exchange membrane (PEM) fuel cells have advantageously been provided with porous, hydrophilic reactant gas flow field plates, typically with either the fuel or oxidant reactant gas plate having coolant flow field channels provided as grooves extending inward from the surface opposite to the surface having reactant gas flow field grooves formed therein. These have been referred to as water transport plates. In many instances, the grooves forming flow fields have been shaped to provide various operational objectives. Provision of shaped grooves, with sufficient dimensional tolerance, has required end milling, or similar processes which are time-consuming and expensive. Provision of coolant grooves on opposite sides of flow field plates from reactant grooves also require the use of end mills for precise depth and positioning.
Usage of porous, hydrophilic reactant and coolant flow plates have proven to be particularly advantageous in fuel cells providing energy to drive electric vehicles. However, the utilization in commonly available vehicles is subject to extreme cost restraints in comparison with other fuel cell applications.
A large percentage of the cost of fuel cells currently powering electric vehicles is the cost of producing the reactant and/or coolant flow field plates.